Electrical apparatus.



HA. CHURCHWARD. v ELECTRICAL APPARATUS. APPLICATION FILED APR-'23. I 9I a.

' Patented May 1. 1917.

.amxsn'nm cauncnwm, or nosron, MAssAc Hose rrs, ASSIGNOR r A-B-C sun'rnn OOMPLKY OF DETROIT, MICHIGAN, A CORPORATION OF. MICHIGAN.

- nnncrnrchn Arrhmxrrrs.

I Yilcll 'l'vlmm it may con ern:

itknown that I, ALl -XANDER (Immenwvaan, a citizen of the United States, reslding at Boston, in the county of Suffolk and vState of Massachusetts, have invented certain new and useful Improvements 1n Electrur-a-l Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others Skilled in the art to which it appertains to make and use the same. I

The presentinvention relates to electrlcal apparatus and more particularly to electric motors or generators comprising a revolving armature and a stationary field.

It is desirable with this type of apparatus, and more particularly. in the smaller units that'the electric motor or generator shall be siln'ple and compact in its construe 'tion and have a minimum number of parts to enable the ap n1ratus to be constructed at a eom] ara'tivelv .low cost, and obtain a finished product which is light in weight and occupies a minimumof space.

i a "The object of the present inrcntion is to provide certain new and useful improvements in the POllStl'ill'tlOl] of a. nmtor or' gene rator of this type lmving a revolvin g'armatare and awsta-tionary field, tending to lessen l cost of majlufacture and to produce a superior article. V \Vith this object in 'view the several features of the invention consist in certain novel ,fcat'urcs of construction, combinations and 5 arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the followingdescription.

In the accompanying drawings illustratinn; the preferred form of the invention;

7 Figure 1 represents afplan view partly in section of a motor orgenerator embodying" the several features of the invention; iig. 2 1S a. front clevatlon ofone end p ece re r. in elevation of the end-piece taken upon the line ii -3' of l ig. 2; Fig'. 4 is a side elevation of the rectangular'framecarrying-the pole piece and Fig. 5 is a. section in elevation 50 of the frame taken upon the line 5-5 of- Fig. 4.

The present invention contemplates certain improvements in the construction and arrangement-of the stationary pole pieces ihclosing the revolving armature in order.

flpeciflcationof Letters Paten Application ined April as, 1915. Serial No. 23,329.

wed from the machine: Fig. 3 is .asection iron frame to'prevent themagneticfield Qtangular frame is formed of iron or other Patented May 1, 1917.

to lessen ti 1e cost of manufacture. of the op paratus and to provide a constructlon whlch is compact and light 111- weight. To th s en the revohing armatureis inclosed by a frame having recessesfornied in its oppo- 7 site faces t1) provide curved surfaces located in proximity to the moving surface of the. armature and forming pole piecesfor the armature. In order to limit-the magnetic field to the effective length of thearmatnre the recesses are connter-bored in order that the curved surface forming each pole piece shall terminate at the end of the armature and leave )cyond a free space between the frame and arn'ni ture to form a suitable airgap. I In theillustrated embodiment of the invention an armature 2' is carried upon a shaft 3 and I'OVOlTBS within a frame 4. The

effective length of the armature maybe con-"7 sidered as he substantially cylindrical pop; tion of the armature formed by the iron core of the arma ture, and indicated at ,5, in-Eig. 1. The; present machine is a fourpole machlne, two oi the poles being formed by pole pieces 3 7 which are surrounded by electrical windings-.8. and these pole pieces are secured by set screws 9 upon the ends of the frame which is substantially rectangular in form, r p as shown clearly in Fig.4. Theother 016 '35 faces are conveniently formed by provi ing' recesses 10 which extend in a lengthwise direction tl roughout opposite sides of the frame to provide curved-surfaces located in proximity to the moving surface of the 9 armature at d substantially concentric therewith. .The length of the curved snrfacesfis made to Poll cide substantially with the eflective length Yet the armature by providing counter-bond portions 12;. extending in! wargilyfron the opposite ends of each recess. as shrwn clearly in Figs. 2 and '5: v These count r-boredportions" serve the dual function of providing a. sufiicient air-gaphetween the ends ofthe armature and the,

extendingleyond the pole faces proper, and at the sumetime. serve to guide the end pieces and'p isition them properly with relation to the "name and armature. The recmagnctic material and the end piecesind icatcd resp ctivclyat 14' and '15-are formed of tl-lllllllnllll or other-suitable non ma i netic material. The end pieces 'provi ed lo ios armature by pilot members 16; w m

ids ly in the 'cmmter-bofed or the frame 4, as shown cleerlyin ethe" end pieces are formedeimhmagnetic material the insertion;

preferred to employ the specific I arrangement of deseribede it will be understood mat is eept so far as Specified in the. clei msfand lney be changed or modified- OI}; hjaying 'been. dseribed u ngu1, s:--, v 11'. etch-b1" generator comprising a, re-

e'll'iietnre, a} fraxne inclosing the ar- "fol-the armature shaft 3 and ei" Properly with relation teat 1 mature, counter-v the end pieces en dfl a ie end piece, and pilot members. projecting from the end to osition the end embers into the counter-bored Oes 'net tend. to distort the mug Parts tide-pole bered portions extending inwardly from the matni'e and having 'gforr'ned in the opposite faces to Egov de pole pieces for the ar- 2% red portions extending imwardly frem adjacent ends of the recesses, an

piece 1nd arranged" toengage within the counter-bored portions of the recesses piece properly with reatlon to the frame and armature A motor "or generator comprisingafregiving armature, a frame of me etle material inclosing the armatnre'and aving-recesses formed in its opposite-faces to propieces for the armature, counter ends zo f the recesses, an end piece of neumagnetic mater-i a1, {andpilot members proj ecting from theend pieize and arranged to'be received in the countembore'd' portions of the reces's'es to position the end piece ithi'reIe-I tien to the frame andar natu 'e.

ALE ANDE CHURCHWARD. 

